1,720,957 research outputs found
The Effect of Duration of the Rivet Process on the Strength of Single Lap Joining
No full textGood airplane joining supports aircraft strength. The general joining process is using rivet as joining method. The parameter that affects the strength during the riveting process is the duration of the rivet head formation. The purpose was to determine the effect of the duration of rivet head formation on the quality of the joint. The research was carried out with the help of homemade tools, to ensure data consistency. The selected riveting duration is 3, 4, 5, 6 seconds. After connection, each connection was tested for strength through tensile testing and macro photo images from the joining. Results show that the 5-second duration provides the best connection with the tensile test results of 165 MPa. Based on the macro photo image, the 5 second rivet process produces the best connection because it produces the biggest rivet body so that it provides the greatest strength compared to the others
Karakteristik Minimmum Quantity Lubrication Dengan Pelumas Nabati Terhadap Jarak Potong dan Flank Wear Pahat Carbide
No full textMaching using coolant causing environmental problems. Improper coolant waste handling can damage surrounding environment. In Minimum Quantity Lubrication (MQL) there are lubrication that can reduce friction force between tool and working material thereby can reduce the rate of temperature rise, and can impove tool lifeThe purpose of this research is to analyse the use of vegetable oil lubricant as alternative MQL lubricant on cutting distance and flank wear of the work material.This research using vegetable oils consisted of palm oil, coconut oil, soybean oi, and maize (corn) oil. Those vegetable oils were tested their physical properties to be compared with ester oil especially the kinematic viscosity and flash point properties. Turning process were done until flank wear reach 0.3 mm.Soy beam are choose as the best vegetable oil used as MQL. Compared with dry, MQL soy beam produce longer cutting distance. Compared with wet and MQL ester oil, soy beam oil produce shorter life tool
Keandalan Komponen Nose Wheel Assy pada Pesawat Cessna
Get PDFMaintenance is taken to maintain the reliability of the components that support overall nurse performance. One of them is the landing gear which functions for all aircraft movements on the ground including taking off, landing, taxing and parking, and holding the aircraft's load while on land. Nose wheel assy is provided to hold the nose of the aircraft and maneuver while on the ground. Based on information obtained from the engineering department as well as looking at the maintenance logbook on the ATR 72-500 aircraft there was a problem with the nose wheel assy. Where these problems can result in the movement of the aircraft will be problematic. The method used is the Weibull distribution analysis method, the main objective is to determine the failure rate and the reliability of these components as well as to determine the characteristics of the failure modes caused. The parameters used in this distribution are the shape parameter (β) and the scale parameter (h). From the calculation analysis results, it can be seen that the nose wheel assy component based on time failure will function until it fails at the age of 585 hours 38 minutes and β is 3.513864. Following the provisions that apply to values β >1,the type of failure that occurs is a type of failure to wear out. While based on the cycle will function until experiencing failure at the age of 398 hours 13 minutes and β is 1.258549 Under the provisions that apply to values β >1, type failure that occurs is a type of wear out. This type of failure has the property of increasing the failure rate with increasing use, therefore for nose wheel, assy components more effective preventive maintenance is applied.This type of failure has the property of increasing the failure rate with increasing use, therefore for landing gear, assy components more effective preventive maintenance is applied
PENGARUH VARIASI FRAKSI VOLUME KOMPOSIT SERAT E-GLASS ±45° POLYESTER 157 BQTN TERHADAP KEKUATAN BENDING DAN GESER
No full textDemand of composite as aeronatics material is incresing. It’s light weight, high specific strength, are become a favour of research. Fiber volume Fraction (FVF) is one of important factor on making of composite. The volume ratio between FVF and the resin is affecting its mechanical properties. In this reaserach there were three ratio varation between fiber and the resin. Bending and shear test were conducted through out this research. Results show that, the ductility increased due to the increased of its ratio, but it’s shear stressare decresed
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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